Characterization of the major surface glycoconjugates of Trypanosoma theileri.

Trypanosoma theileri maintains a long-term extracellular infection with a low parasitaemia in bovids. The surface of this parasite is predicted to be decorated with several surface molecules including membrane surface proteases (MSPs), trans-sialidases and T. theileri putative surface proteins (TTPSPs). However, there are no experimental data to verify this hypothesis. Here, we have purified and partially characterized the surface glycoconjugates of T. theileri using biochemical and mass spectrometry-based approaches. The glycoconjugates fall into two classes: glycoproteins and glycolipids. Proteomic analysis of the glycoprotein fraction demonstrated the presence of MSPs and abundant mucin-like TTPSPs, with most predicted to be GPI-anchored. Mass spectrometric characterization of the glycolipid fraction showed that these are mannose- and galactose-containing glycoinositolphospholipids (GIPLs) that are larger and more diverse than those of its phylogenetic relative T. cru z i , containing up to 10 hexose residues and carrying either alkylacyl-phosphatidylinositol or inositol-phospho-ceramide (IPC) lipid components. [Display omitted] • The surface of Trypanosoma theileri is heavily glycosylated and like that of Trypanosoma cruzi. • Many T. theileri putative surface proteins (TTPSPs) are expressed in T. theileri cultured cells. • Most expressed TTPSPs are glycosylphosphatidylinositol (GPI)-anchored proteins. • T. theileri cultured cells express abundant and relatively large glycoinositolphospholipids (GIPLs). [ABSTRACT FROM AUTHOR]